If there is a choice available then I am using any 95 octane, E5, with Millers Oils VSPe Power Plus – Multi-shot added at 1cc : 1litre fuel, or EssO "Synergy Supreme +99 (E5), the latter is an E5 fuel, with additional octane booster. This is in the 1974 Ducati 450 MKIII, 1991 Yamaha SRX600 and the 1988 Honda Bros 400. When I was trying to get the 1979 Moto Morini 125H to run, with the Heron head, I was using these fuels as well.
If only 95 octane, E10 is available, I still use it and add Millers Oils VSPe Power Plus – Multi-shot added at 1cc : 1litre fuel. My reason for using Millers, is that it stabalizes the fuel, if I should have to leave the machine idle for any length of time (more than 4 to 6 weeks), it is economical in use at 1cc : 1litre and my local garage gives me a good price on the 500ml bottle that I decant into another measuring container produced by Briggs and Stratton for their garden machinery fuel stabiliser and fits in the tool bag.
If you are unlikely to leave a machine unused for more than 6 weeks, the additive might be a bit of overkill, as the fuel should be fairly stable, yet tend towards being hygroscopic, because of the ethanol. Any idle time longer than this then I would either drain the fuel from the carbs and fuel tank, or add the Briggs and Stratton/ Castrol "Classic" Lead Replacement and E10 Additives, running the engine, with the additive in the fuel to ensure that it passes into the carburettor. I usually, still drain the float bowl and leave it open to atmosphere.
All of the engines are producing a rich cocoa brown colour to the lower ⅔ part of the plug insulator and I find that they have a good "pick up" and steady running. I tend to run the engines a wee bit rich, rather than on the weak side, but the Ducati still has the occasional "spit back" when opening the throttle from the pilot onto the slide, when the weather gets hot. It's what happens when you run carbs and not injection systems, engine management systems etc. etc. etc., with E fuels.
Like George (blethermaskite) and recommended to me by Nigel, instead of using the NGK BH6S, as recommended by NGK, I am using the NGK BH7S plug and that has made a big difference to plug colour. With the NGK BH6S, I was always tending towards a white insulator, with a slight tan ring about a third of the way down from the nose and some slight blistering on the ground electrode tip. With the NGK BH7S there is no blistering at all and Nigel mentioned going to the cooler NGK BH8S when racing, but the 450 is only on the road.
If you really want to read up about the whole ethanol/fuel subject, then use the following link, it makes my brain hurt!
IEA-AMF_ethanol_properties_etcHappy reading!
Bill
I am running everything 'old' that I have on super unleaded simply on the basis that in theory it has the least ethanol blended in, in fact one major petrol refining company advised me that their super unleaded had no ethanol in it at all. When they removed tetra ethyl lead from petrol (completely erroneously on some half baked 'green' agenda) I with some trepidation started to use super unleaded with a range of 'quack snake oil' additives and it worked ok for me, I eventually stopped using the additives and again all seemed well without them.......so to date all seems ok with the two Ducati's.